Proton beam therapy in paediatric cancer: Anticipating the opening of the Australian Bragg Centre for Proton Therapy and Research.

Proton Beam Therapy (PBT) has the potential to improve paediatric cancer care by reducing radiation exposure and thus long-term toxicities. Ethical concerns and debates surrounding the treatment, such as eligibility and accessibility, are ongoing in Australia. The Australian Bragg Centre for Proton Therapy and Research (ABCPTR) (named after Sir William Henry Bragg who described the Bragg peak in his laboratory at the University of Adelaide in 1903) aims to increase access to PBT in Australasia and offer a patient-centred care approach. Research is underway to assess PBT's safety and cost-effectiveness, using tools including Normal Tissue Complication Probability (NTCP) models. Collaborative efforts are focused on developing tailored survivorship clinics to enhance patient follow-up and quality of life. With the anticipated opening of the ABCPTR, Australia is preparing to take a significant step in radiation oncology, offering new research opportunities and creating a publicly funded treatment centre. The initiative aims to balance treatment efficacy with patient care, setting the stage for a future in which radiation therapy will reduce long-term side effects compared to the current standard of care. The implementation of PBT in Australia represents a complex and promising approach to paediatric oncology. This article provides an overview of the current landscape, highlighting the potential benefits and challenges of a treatment that could redefine the quality of survivorship and contribute to global research and best clinical practice.

Cochlear sparing in LINAC-based radiosurgery for vestibular schwannoma: a dosimetric comparison of dynamic conformal arc, IMRT and VMAT treatment plans.

BACKGROUND: Stereotactic radiosurgery (SRS) is the preferred treatment for vestibular schwannoma (VS) in patients with preserved hearing and tumour diameter < 3 cm. Emerging evidence suggests restricting cochlear dose could preserve hearing. This retrospective replanning study aims to compare dynamic conformal arc therapy (DCAT), intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans for superiority of cochlear dose sparing without compromising tumour coverage. METHODS: Eligibility criteria included sporadic VS, serviceable hearing and availability of CT and MRI for planning. The original gross tumour volume and brainstem OAR volume were retained; the cochlea was newly contoured on the planning CT scan (bone window). Each case was replanned using the three above techniques, prescribing 12 Gy to the 80% isodose line. No dose constraint was applied to the cochlea. RESULTS: Eighteen patients were replanned. Mean tumour volume was 2.25 cc. Tumour coverage and tumour mean dose (DCAT: 14.2, IMRT: 14.6, VMAT: 14.5 Gy) were comparable. Paddick and RTOG conformity indices were better for DCAT (0.66 and 1.6) and VMAT (0.69 and 1.5) compared to IMRT (0.56 and 1.9). DCAT had superior gradient index (3.0) compared to VMAT (3.4) and IMRT (3.4). VMAT delivered the lowest mean brainstem maximum dose (8.3 Gy) and decreased the mean cochlear dose (3.4 Gy) by 2.3 and 2.1 Gy, and the mean cochlear maximum dose (3.6 Gy) by 2.4 and 2.5 Gy relative to DCAT and IMRT, respectively. CONCLUSION: LINAC-based SRS treatment using VMAT can achieve better cochlear dose sparing than DCAT or IMRT while maintaining tumour coverage.

The Effect of Cochlear Dose on Hearing Preservation After Low-Dose Stereotactic Radiosurgery for Vestibular Schwannomas: A Systematic Review.

Purpose: Despite excellent tumor control after stereotactic radiosurgery (SRS) for vestibular schwannoma (VS), the hearing preservation rate remains unsatisfactorily low. Although many factors have been associated with hearing loss, the dose to cochlea has gained more interest in recent years. However, studies investigating the relation between cochlear dose and hearing outcomes have produced inconsistent results. The purpose of this work is to systematically review the literature and critically analyze the studies that investigated the correlation between cochlear dose and hearing loss. Methods and Materials: A literature search of Ovid MEDLINE, Embase, and Scopus was performed. Studies were included if the SRS dose used was 11 to 14 Gy and included adult patients with sporadic VS, initially serviceable hearing, and at least 24 months of mean or median follow-up. Results: Twenty-one cohort studies and 1 case-control study were eligible for inclusion, and none were considered to be truly prospective. There was substantial heterogeneity between studies in terms of baseline hearing status, cochlear dosimetry, definition and reporting of hearing outcome, and duration of follow-up, limiting comparison between studies and precluding formal meta-analysis. Eleven studies showed a statistically significant correlation between cochlear dose and hearing outcome, but there was considerable variation in the reported cochlear dose parameter that predicted hearing outcome and whether it was an independent predictor. The definition of hearing outcome and whether the outcome variable is continuous or dichotomous have a bearing on the reported correlation between cochlear dose and hearing outcome. Conclusions: Whether cochlear dose is a predictor of hearing preservation after SRS for VS could not be unequivocally determined. Future studies should use consistent cochlear dosimetry and hearing outcomes for reliable assessment. In the meantime, based on currently available data, a practical approach will be to aim for a mean cochlear dose <4 to 6 Gy without compromising tumor dose.

Survey of brachytherapy training experience among radiation oncology trainees and fellows in the Royal Australian and New Zealand College of Radiologists (RANZCR).

INTRODUCTION: To evaluate brachytherapy training experience among trainees and fellows trained through the Royal Australian and New Zealand College of Radiologists (RANZCR). METHODS: All current trainees and fellows (who obtained fellowship from 2015 onwards) were sent an online anonymous questionnaire on various aspects of brachytherapy training, including number of cases observed/ performed, opinions on brachytherapy assessment during training, barriers to brachytherapy training and future role of brachytherapy. RESULTS: The overall survey response rate was 24% (40/161 trainees, 30/126 fellows). Of the 70 respondents, 50 (71%), 38 (54%) and 43 (61%) reported to have received formal brachytherapy teaching from radiation oncologists, radiation therapists and medical physicists respectively. Most respondents had exposure to gynaecology brachytherapy - two-thirds of trainees and all fellows have performed at least one gynaecology brachytherapy procedure. Prostate brachytherapy exposure was more limited - by the end of training, 27% and 13% of fellows did not have exposure to LDR and HDR prostate brachytherapy. More than two-thirds indicated there should be a minimum number of brachytherapy case requirements during training, and half indicated that trainees should be involved in ≥6 gynaecology brachytherapy procedures. Barriers affecting training include lack of caseload (70%) and perceived decreasing role of brachytherapy (66%). Forty-three percent of respondents were concerned about the decline in brachytherapy utilisation. CONCLUSION: This is the first survey on brachytherapy training experience among RANZCR trainees and fellows. It highlighted limited brachytherapy exposure during RANZCR training, and the need to revisit brachytherapy training requirement in the current training programme, along with long-term brachytherapy workforce planning.

Non-melanoma skin cancer in general practice: Radiotherapy is an effective treatment option.

BACKGROUND: Skin cancer is the most common malignancy that is managed in general practice, and non-melanoma skin cancer (NMSC) comprises the vast majority of presentations. Radiation therapy (RT) plays an important part in the management of NMSC and may be used as definitive treatment for low-risk cancers, as an adjuvant treatment for high-risk disease or alone for inoperable cases. OBJECTIVE: The aims of this article are to discuss: 1) types of RT; 2) role of RT, including its advantages and disadvantages; 3) side effects (toxicity) of RT; 4) outcomes from RT; 5) low- versus high-risk NMSCs and 6) some guidelines for general practitioners on when to refer patients for consideration of RT. DISCUSSION: The primary goal of treatment for NMSC is to cure the patient, and a secondary goal is to provide the best cosmetic and functional result with the minimum impact on quality of life. In deciding what modality of treatment to use, clinicians will need to take into account the site of the tumour, clinical stage, histological subtype and any high-risk features, patient comorbidities as well as patient preferences. RT provides a safe and effective alternative to surgery in select cases and is particularly useful for the elderly or where surgery might have a negative impact on function or cosmesis.